I will be inspecting a house with a geothermal heating-cooling system “water furnace” I would like to have some pointer on that system, I’ve heard about them, somewhat studied them but never seen one. Any info on what to inspect will be greatly appreciated
Thank Jeannot
Try here
http://www.reddawn.com/featart11-98.html
http://www.dougrye.com/geothermal.html
http://www.geothermalheatpump.com/
Roy Cooke
http://nachi.org/forum/showthread.php?t=11838&highlight=waterfurnace
The type of water loop / supply is important.
http://www.waterfurnace.com/content.aspx?section=residential&page=loop
Service is recommended annually.
Thank you everyone,so nice to have this message board so many replies within the hour
Thank you
Jeannot
Jeannot: I would recommend checking the geo unit like any other heat pump. 1. Ensure the reversing valve operates in both open and closed position. 2. You may have or may not have an emergency heat mode that operates depending on the installing contractor and or the MFG you should under normal circumstances be able to determine this by observing the thermostat that will say emergency heat as an option. 3. You may or may not have a glycol loop as some are strictly water. There will be a pump to distribute the liquid thru the loop and I check the pump and all fittings that are visible for leakage particularly the pump seal. Geo units can appear ominous simply because every thing is stuck in one cabinet but in all actuality are not much different than a air to air heat pump.
I think I posted this once before but here goes again. The MFG’s sales hype that some of the others linked to leads a person to believe that these units are the best thing since sliced bread as to the cost of operation. Keep in mind that on a geo unit you still are paying the cost of operating a compressor and a fluid pump at the same time and this cost is incurred when ever the unit is operated heat and or cool year round. Thus the life expectancy is less on the compressor than a conventional A/C unit.
Amps X Volts= Watts and watts is what you pay for???
With the price of propane being what it is today a rural property that has a well insulated home could very likely be ahead money wise to install a geo unit but the cost of operation of these units still does not compare to natural gas. As Robert O states that my 2 cents.
Charlie, do we need to discuss this?
Maybe I’m not getting your drift but cooling/heating a condenser with 56° water beats 32°/ 95° DX coils!?
Lower head pressure equals lower power consumption and stress on the compressor.
Geothermal doesn’t require a defrost cycle where the air-conditioner comes on with the heat strips.
The compressor doesn’t have to slam between air conditioning and heating during a defrost cycle.
It seems that there is some savings and lack of abuse with geothermal equipment?!?
Am I missing something?
David I am just hard headed of course a compressor will draw less amps with less head pressure we both know this. I am just stating if you operate two compressors one for 6 months out of the year and one for 10 months out of a year its just like a automobile the little old lady whom drives 10,000 in 5 years or the Hi that drives 100,000 per year who is going to be replacing their vehicle first.
If a compressor is designed to operate say for example 17 amps it will draw that, just because you run 55 degree degree water thru the condenser does not mean that the amps start decreasing, the compressor will draw what its designed minimally to draw the amps of course increase with the head pressure increasing. David I am not trying to give you lesson here just stating my thoughts so others might follow along.
I am not putting down Geo units I think they are a great option to burning propane. I would have to think otherwise in favor of natural gas.
Okay, I see now that you are comparing gas with a heat pump!
If the run load amps is rated for 17 amp draw, it should never be operated above 17 amps. However, if you put 55° water through the condenser instead of 95° air, the run load amps will be below 17. No?
Most geothermal units operate below the rate amperage drawn consistently.
I believe our misunderstanding here is that we are comparing different units designed completely different from one another.
When we discuss compressor load and lifespan only, a DX heat pump runs under much less power consumption and load in the winter than a geothermal unit in the heating mode. Therefore, a geothermal unit is under greater strain in the wintertime and will wear out quicker.
However, if we are looking at power savings, the geothermal does not use auxiliary heat or a defrost cycle like the DX heat pump. So the DX heat pump consumes more power.
Now when we look at the really big picture (total money spent), we have to look at increased equipment costs, increased maintenance costs versus overall life expectancy of the equipment when we look at the bottom line.
As you are pointing out, there may not be much of a difference in total lifespan (depending on the equipment compared).
We’re just not viewing this issue from the same side of the fence! 
No David I would not even consider comparing a Geo unit to an air to air as to operating cost, no comparison.
I was just trying to make a point of total operating time on the compressor per year on a geo unit as compated to natural gas heat. I don’t have any real stats on the life expectancy of the geo unit but my thinking is just based on the overall run time per year.
I don’t recall what the actual amp draw or FLA on a geo unit is but common sense dictates that it would be less due to the colder condenser temps.
If a geo unit is designed 10, 12, or 15 amps or whatever, thats what it will draw when ever that compressor is running. Just trying to compare that cost to the cost of natural gas. Perhaps my thoughts are not clear You Know I failed my English/grammer in school:)
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Now that makes sense!
Many geo units in Central Indiana use a pond for its water source. Their obvious issue is getting plugged up with debris. Some others use a well and discharge back into another well. That practice I believe is now illegal due to possible groundwater contamination. Closed loop is the best way to go. $$$$ saved versus natural gas in IN is now significant.
If the price of natural gas keeps going up as its doing there will be a bunch of folks looking at geo units, but most don’t have sufficient yard for a buried loop so I don’t think they will put the gas company out of business.
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I went to some training on these systems last Fall and was informed that an alternate to a ground loop is a drilled well or if available a pond or stream to place the loops in with a permit from the state Natural Resources Dept.
This true but have also heard wild stories about the loop not standing the test of time and contaminating the pond with glycol. Not a problem if you are using well water no glycol.
Systems most common in this area are a vertical loop. (No Glycol)
I have only found a glycol circulating medium in solar type systems.
I can understand that Joe no one back East has any land, yards not larger than a postage stamp have to go vertical.
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Any info/details in inspecting a HVAC new (2008) Geothermal unit (Closed loop).
Have anyone conducted an inspection in Florida? Feeback is ppreciated.
Thanks!